I've almost ordered a HV oil pump form Melling (m-select 10550) but I did some research and it seems that there are a lot of people against using Hv pumps.
Most reasons against are:
1. Too much volume will make pump recirculate extra volume and cause
oil foaming and heating.
2. Possible oil starvation on continuous hig rpms.
3. Premature distributor (or even cam) gear
4. HP loss
5. Both CompCams and Crane advise not to use HV pumps with their cams

And here is link to "myths" on Mellings site:
[URL="http://www.mellingselectperformance.com/Portals/5/pdf/pdf_catalog/high-volume-pumps.pdf"]http://www.mellingselectperformance.com/Portals/5/pdf/pdf_catalog/high-volume-pumps.pdf[/URL]

Now, I know that nobody will tell that their product is bad, but they also make std volume pumps at the same price as HV, so I don't see why would they lie.

And now, what is most important to me, what should I use, HV or STD?
This is what I'll use in bottom end:
- stock crank, repolished (so clearances might be a little higher, good for HV pump?)
- std/std main/rod bearings
- Canton RR oil pan (7qt)
- hyd roller cam
- ls lifters

I have heard a high pressure pump is better than a high volume pump.

The old days of "more pressure is better" are over. With those mods (minimal) you should be fine with a standard pump.

That said, I have a HV pump in my 383 and it's fine. I bought it before I did the research.

Quote:

Not totally, Jon, at least not with a dry sump. But I agree that a std. will be fine on an LT1.

I've always used high pressure high volume pumps. I've heard lots of myths on the forums about robbing horsepower and camshaft failure and all that. Never happened to me, I think some guys just shouldn't build their own engines is the issue.

I've always liked the idea because if you go with a turbo or blower down the road that needs oiling, you have the capacity. I've never seen one pump an oil pan dry either, if that happens the block has sludge in the top. That's just silly talk.

However, there is one phenomena that you have to be careful about with high oil pressure is your hydraulic lifters. Some crap lifters will pump rock hard and hang the valve open a hair.

-- Joe

I just followed GM's lead on this thing and went with a higher pressure oil pump like was used on the Z28. I figure GM would know more about engine oiling than me.